This study was based on two years of field observations of a Linnaea borealis population in a coniferous forest in Sweden. Detailed information on performance and survivorship of shoots were gathered from consecutively made drawings of 90 individually marked shoot systems of Linnaea distributed among 15 plots in the forest. Branching of the shoot systems was correlated to growth of the main shoot. Increasing light flux negatively affected growth of Linnaea. A tendency for a competitive effect on Linnaea of Vaccinium spp. was also found. In contrast, the surrounding mosses, and intraspecific density of Linnaea had no significant effect on the shoot systems. The growth rate of the shoot population was analysed by matrix models. Population growth rate was most dependent on survivorship and growth of main shoots in Linnaea, while the survivorship of alteral shoots was of less importance. In spite of an average decrease in the population size as revealed by the matrix model stimulation, the incorporation of the observed spatial variation in shoot growth increment, branching and shoot survivorship, yielded varying population growth rates. Parts of the population increased in size. The importance of choice of spatial scale in population analyses of forest understory plant is emphasized.